emp diarrea
TRANSCRIPT
-
8/9/2019 Emp Diarrea
1/20
July 2004Volume 6, Number 7
Authors
Michael D. Burg, MD, FACEP
Residency Program Director, Department of
Emergency Medicine, Onze Lieve Vrouwe Gasthuis
(Hospital), Amsterdam, The Netherlands.
Hoori Hovanessian, MD, FACEP
Assistant Clinical Professor, Department of
Emergency Medicine, UCSF–Fresno, University
Medical Center, Fresno, CA; Presbyterian
Intercommunity Hospital, Whittier, CA.
Peer Reviewers
Andy Jagoda, MD, FACEP
Vice-Chair of Academic Affairs, Department of Emergency Medicine; Residency Program Director;
Director, International Studies Program, Mount Sinai
School of Medicine, New York, NY.
Earl J. Reisdorff, MD, FACEP
Director of Medical Education, Ingham Regional
Medical Center; Associate Professor, Michigan
State University Emergency Medicine Residency,
Lansing MI.
CME Objectives
Upon completing this article, you should be able to:
1. construct a broad differential diagnosis for
diarrheal illness in adults and children;
2. describe aspects of a targeted history and physicalexamination for patients with diarrhea, including
indications for diagnostic testing;
3. identify ED patients at high risk for serious or
life-threatening diarrheal illnesses; and
4. describe treatment strategies for ED patients
with diarrhea.
Date of original release: July 1, 2004.
Date of most recent review: June 15, 2004.
See “Physician CME Information” on back page.
Associate Editor
Andy Ja goda, MD, FACEP,Vice-Chair of Academic
Affairs, Department of
Emergency Medicine;
Residency Program Director;
Director, International Studies
Program, Mount Sinai School of
Medicine, New York, NY.
Editorial Board
William J. Brady, MD, Associate
Professor and Vice Chair,
Department of Emergency
Medicine, University of Virginia,
Charlottesville, VA.
Judith C. Brillman, MD, Professor,
Department of Emergency
Medicine, The University of
New Mexico Health Sciences
Center School of Medicine,
Albuquerque, NM.
Francis M. Fesmire, MD, FACEP,
Director, Heart-Stroke Center,
Erlanger Medical Center;
Assistant Professor of Medicine,
UT College of Medicine,
Chattanooga, TN.
Valerio Gai, MD, Professor and
Chair, Department of Emergency
Medicine, University of Turin,
Italy.
Michael J. Gerardi, MD, FAAP,
FACEP, Clinical Assistant
Professor, Medicine, University
of Medicine and Dentistry of
New Jersey; Director, Pediatric
Emergency Medicine,
Children’s Medical Center,
Atlantic Health System;
Department of Emergency
Medicine, MorristownMemorial Hospital.
Michael A. Gibbs, MD, FACEP,
Chief, Department of
Emergency Medicine,
Maine Medical Center,
Portland, ME.
Gregory L. Henry, MD, FACEP,
CEO, Medical Practice Risk
Assessment, Inc., Ann Arbor,
MI; Clinical Professor, Department
of Emergency Medicine,
University of Michigan Medical
School, Ann Arbor, MI; Past
President, ACEP.
Francis P. Kohrs, MD, MSPH, Lifelong
Medical Care, Berkeley, CA.
Keith A. Marill, MD, Emergency
Attending, Massachusetts
General Hospital; Faculty, Harvard
Affiliated Emergency MedicineResidency, Boston, MA.
Michael S. Radeos, MD, MPH,
Attending Physician, Department
of Emergency Medicine, Lincoln
Medical and Mental Health Center,
Bronx, NY; Assistant Professor in
Emergency Medicine, Weill College
of Medicine, Cornell University,
New York, NY.
Steven G. Rothrock, MD, FACEP,
FAAP, Associate Professor of
Emergency Medicine, University
of Florida; Orlando Regional
Medical Center; Medical Director
of Orange County Emergency
Medical Service, Orlando, FL.
Alfred Sacchetti, MD, FACEP,
Research Director, Our Lady of
Lourdes Medical Center, Camden,
NJ; Assistant Clinical Professorof Emergency Medicine,
Thomas Jefferson University,
Philadelphia, PA.
Corey M. Slovis, MD, FACP, FACEP,
Professor of Emergency Medicine
and Chairman, Department of
Emergency Medicine, Vanderbilt
University Medical Center;
Medical Director, Metro Nashville
EMS, Nashville, TN.
Charles Stewart, MD, FACEP,
Colorado Springs, CO.
Thomas E. Terndrup, MD, Professor
and Chair, Department of
Emergency Medicine, University
of Alabama at Birmingham,
Birmingham, AL.
EMERGENCY MEDICINE PRACTICEA N E V I D E N C E - B A S E D A P P R O A C H T O E M E R G E N C Y M E D I C I N E
EMPRACTICE.NET
Diarrhea: Identifying Serious
Illness And Providing Relief It’s a stormy day, yet the ED is furiously busy. As you pick up your next patient’s chart,
you glance at the chief complaint—diarrhea. “Why would anyone come out on a day
like this, for something like that?” you wonder. Then your eye catches the patient’s age
(60) and vital signs—temperature, 38.7˚C (101.7˚F); pulse, 124 beats per minute;
respiratory rate, 24 breaths per minute; blood pressure, 102/50 mmHg. This man seems
a bit sicker than the run-of-the-mill diarrhea patient. A quick glance into his room
confirms your suspicion; he’s pale, sweaty, ill-looking. He clearly needs help. But is an
extensive work-up really going to be cost-effective—and won’t it keep you from treating
other patients in a timely manner? Besides, don’t most of these cases run their course
with a little help from fluids and symptomatic treatment?
DIARRHEA is a common condition that can stem from many causes.Fortunately, the care of the ED patient with diarrhea is usually straightfor-ward—a targeted history and physical examination, followed by symptomatic
remedies. However, the temptation to dismiss a case as “just diarrhea” can be
quite dangerous, as serious disease processes can present with diarrhea as the
chief complaint. Some patients require more systematic investigation or even
hospitalization. Clinical judgment based on the current evidence can help guide
a cost-effective work-up of patients with diarrhea that will identify patients
with more severe etiologies or at risk for complications.
Critical Appraisal Of The Literature
Given that diarrhea is such a ubiquitous part of the human condition, it’s notsurprising that the literature on the subject is truly voluminous. Thousands of
studies address the epidemiology, etiology, pathophysiology, evaluation,
treatment, differential diagnosis, and other features of patients with diarrhea.
Thankfully, a number of well-done reviews, meta-analyses, and position
statements from expert medical organizations condense the findings, making
the job of the practicing emergency physician caring for patients with diarrhea
much easier.1-19
In general, the preponderance of evidence tends to support the following
practices in patients with diarrhea:
-
8/9/2019 Emp Diarrea
2/20
COPYRIGHTEDMATERIAL—D
ONOTPHOTOCOPYORDIST
RIBUTEELECTRONICALLYWITHOUTWRITTENCONSENTO
FEBPRACTICE,LLC
Emergency Medicine Practice 2 EMPractice.net • July 2004
• Evaluating the patient: The presence of a dry axilla
supports the diagnosis of hypovolemia, and moist
mucous membranes and a tongue without furrows
argue against it. In adults, the capillary refill time and
poor skin turgor have no proven diagnostic value.3
Acute body weight changes provide the best measures
of dehydration in children. Mucous membrane
hydration, capillary refill time, absence of tears, and
alterations in mental status are the next best associated
measures.4 Important features of the history include
how the illness began; stool characteristics (frequency
and quantity); travel history; occupation; day care
center attendance or nursing home residence; whether
the patient has ingested raw or undercooked meat, raw
seafood, or raw milk; whether the patient’s contacts are
ill; the patient’s sexual contacts, medications, and other
medical conditions, if any.2,5 Red-flag findings include
severe dehydration, bloody or febrile diarrhea, or
illness in infants, elderly, or immunocompromised
patients.5 Serial evaluations over several hours can
improve the diagnostic accuracy in patients in whom
the etiology is unclear.1
• Laboratory testing: Routine testing for specific
pathogens is not recommended.4 Reserve laboratory
testing and stool cultures for select circumstances.
Criteria vary but often include bloody diarrhea,
weight loss, diarrhea leading to dehydration, fever,
neurologic involvement, sudden onset of severe
abdominal pain, persistent (> 7 days) diarrhea, or
possible community-acquired diarrhea, traveler’s
diarrhea, or nosocomial diarrhea.2,5 Maintain a lower
threshold for ordering if the patient is pediatric,
elderly, or immunocompromised.2
• Rehydration: Initiate rehydration (oral wheneverpossible).5 In children, clear liquids are not recom-
mended as a substitute for oral rehydration solutions or
regular diets to prevent or treat dehydration.4
• Diet: Refeeding of the usual diet at the earliest opportu-
nity should be encouraged to prevent or limit dehydra-
tion. Very frequent (e.g., every 10-60 minutes), small
feedings may be better tolerated if vomiting is present.
The BRAT diet (bananas, rice, applesauce, and toast)
affords no advantage unless these foods are part of the
regular diet.4
• Medications: Antibiotic therapy can reduce illness
duration by one or two days in most cases. Criteria forempiric antibiotic therapy vary, but consideration of
risks must be weighed against any potential benefits. In
children, antimicrobial therapies are recommended
only when special risks or evidence of serious bacterial
infection is present.4 Institute selective therapy for
traveler’s diarrhea, shigellosis, and Campylobacter
infection.5 Avoid administering antimotility agents with
bloody diarrhea or proven infection with Shiga toxin-
producing Escherichia coli.5 Anti-diarrheal agents and
antiemetics are not recommended for use in children
with acute gastroenteritis.4
Etiology, Epidemiology, And Pathophysiology
Etiology
Diarrhea is a change in normal bowel movements character-
ized by an increase in the water content, volume, or
frequency of stools. Fluid secretion into the gut and
increased gut motility together produce both the increased
stooling frequency and the increased stool liquidity.16,20 The
passage of more than 200 grams of stool per day is consid-
ered to be diarrhea; two to three bowel movements per dayis the upper limit of normal.
An episode of diarrhea lasting 14 days or less is
generally defined as “acute diarrhea,” while “persistent
diarrhea” refers to episodes lasting longer than 14 days.
“Chronic” diarrhea is generally defined as diarrhea that
lasts more than 30 days.
Epidemiology
Virtually every human being experiences diarrhea at some
point. Causes may range from the mild to the life-threaten-
ing, although the clinical course is generally brief and self-
limited in developed nations. However, worldwide,
diarrheal illnesses are the second most common cause of
death and the leading cause of death in children.21
Diarrhea is a common cause of morbidity even in the
United States. The number of hospital admissions due to
gastroenteritis in the United States is estimated to be 450,000
per year.20 Additionally, the U.S. prevalence of chronic
diarrhea approaches 5%.22
Pathophysiology
Diarrhea is broadly categorized as one of two types—either
secretory or osmotic.
The poorly named secretory diarrhea actually occurs
due to abnormal electrolyte transport across the intestinalepithelial cells. Increased secretion and/or decreased
absorption result. The diarrhea is not related to the intestinal
contents and therefore typically does not stop with fasting.
Infection (e.g., cholera) is the most common cause of
secretory diarrhea. The fluid losses can be enormous.
Osmotic diarrhea results from the presence of non-
absorbable solute that exerts an osmotic pressure effect
across the intestinal mucosa, resulting in excessive water
output. Because the diarrhea is caused by the solute, it tends
to stop during fasting. Sorbitol, a poorly absorbed sugar, is
capable of causing osmotic diarrhea.20
Another way that diarrhea is commonly classified is as
infectious vs. noninfectious or inflammatory vs. non-inflammatory. Symptoms such as fever, bloody diarrhea,
and severe cramping suggest an invasive bacterial pathogen
such as Shigella, Salmonella, Yersinia, or Campylobacter. The
presence of nausea and vomiting strongly suggests a viral
agent, and prior antibiotic use suggests possible Clostridium
difficile enteritis. Absence of these factors suggests a non-
infectious cause. Inflammatory diarrhea can be bloody and
associated with fever and abdominal cramps. The causes
can be infectious or non-infectious. Non-inflammatory
diarrhea tends to be watery and can be associated with
nausea, vomiting, and abdominal cramps.
-
8/9/2019 Emp Diarrea
3/20
COPYRIGHTEDMA
TERIAL
DONOTPHOTOCOP
YORDISTRIBUTEELECTRON
ICALLYWITHOUTWRITTENC
ONSENTOFEBPRACTICE,LLC
3 Emergency Medicine PracticeJuly 2004 • EMPractice.net
Differential Diagnosis
The differential diagnosis of diarrhea with abdominal pain
is vast. While patients who present with vomiting, diarrhea,
and abdominal cramps and who have benign abdominal
examinations may seem like clear-cut cases of gastroenteri-
tis—and most patients will respond well given rehydration
and antiemetics—it is important to be aware that the
differential diagnosis includes more severe etiologies that
require different management approaches. (See Table 1.)
Infectious Enteritis
Infectious causes of diarrhea are commonly seen in the ED.
Ingestion of contaminated food or water is the typical
culprit; recent travel, exposure to other ill persons, recent
hospitalization, child care center attendance, and nursing
home residence should all raise the index of suspicion. (See
Table 2 on page 4.)
Common bacterial agents include Campylobacter,
Salmonella, and Shigella species, as well as E. coli. Viral
infections may be caused by rotavirus, Norwalk virus,
cytomegalovirus, herpes simplex virus, and viral hepatitis.
In developed countries, parasitic diarrhea is generally only a
concern among travelers and those with prolonged diar-
rhea. Parasites that cause diarrhea include Giardia lamblia,
Entamoeba histolytica, and Cryptosporidium.2
Signs and symptoms such as bloody diarrhea, weight
loss, diarrhea leading to dehydration, fever, prolonged
diarrhea (3 or more unformed stools per day, persisting
several days), neurologic involvement (such as paresthesias,
motor weakness, cranial nerve palsies), and/or severe
abdominal pain may suggest infectious causes and drive the
need for laboratory testing, especially in young, elderly, or
immunocompromised patients.2
Irritable Bowel Syndrome
Patients with irritable bowel syndrome can have abdominal
pain or discomfort, constipation, diarrhea, or an alternating
course of constipation and diarrhea. A mucoid rectal
discharge is present in about half of afflicted patients.23
Evaluation of these patients fails to produce an organic basis
for the disease; patients do not experience weight loss, fever,
or rectal bleeding. While symptoms vary from person to
person, irritable bowel syndrome is typically characterized
by abdominal pain or discomfort for at least 12 weeks out of
the previous 12 months; abdominal pain that is relieved by
having a bowel movement; and changes in frequency or
appearance of stool when an episode starts. Eliciting a
history suggestive of irritable bowel syndrome requires
referral to exclude more serious disease processes.
Table 1. Typical Characteristics Of Different Etiologies Of Diarrhea.
Infectious
Viral gastroenteritis
Diarrhea with aches, chills, cold symptoms, nausea or
vomiting; history suggesting recent consumption of
contaminated food or exposure to other ill persons,
especially day care; with or without fever
Bacterial diarrhea or GiardiaDiarrhea, history suggesting recent consumption of contami-
nated food, with or without fever (see Table 2 on page 4)
Traveler’s diarrhea
Recent foreign travel, prolonged illness (see also Table 3 on
page 6)
Functional bowel disorders
Irritable bowel syndrome
Variable symptoms but prolonged course; bowel move-
ments that alternate between constipation and diarrhea,
especially if episodes are related to stress
Intestinal obstruction
Severe abdominal pain along with nausea, vomiting, anddiarrhea
Fecal impaction/other blockage
Chronic constipation followed by recent watery diarrhea
Inflammatory
Inflammatory bowel disease (includes Crohn’s disease and
ulcerative colitis)
Frequent bowel movements mixed with blood or mucus
Appendicitis
Vomiting that follows abdominal pain, small amounts of
watery diarrhea (compared to the voluminous amounts
produced as a consequence of gastroenteritis), mild or
absent fever
Vascular
Ischemic bowel disease
Diarrhea, severe abdominal pain, older patient, history of peripheral vascular disease
Malabsorption
e.g., celiac disease or lactose intolerance
Diarrhea, gas, bloating, and stomach pains that seems to be
triggered by certain foods
Medications
Recent new medicine, especially antibiotics, high blood
pressure medications, cancer drugs/radiation therapy,
some herbal medicines
Toxins
Radiation enteritis
Tenesmus, bleeding, and diarrhea stemming from malab-
sorption; can persist for two or three months after
treatment cessation
Arsenic, mushroom poisoning, pesticides, etc.
Varies; usually diarrhea is one of several symptoms
Other systemic conditions
e.g., food allergies, colon cancer, hyperthyroidism
Typically a longer course plus other suggestive symptoms;
see also Table 3 on page 6
-
8/9/2019 Emp Diarrea
4/20
COPYRIGHTEDMATERIAL—D
ONOTPHOTOCOPYORDIST
RIBUTEELECTRONICALLYWITHOUTWRITTENCONSENTO
FEBPRACTICE,LLC
Emergency Medicine Practice 4 EMPractice.net • July 2004
Inflammatory Bowel Disease
Inflammatory bowel disease is a general term that refers to
illnesses that cause chronic inflammation in the intestines,
typically causing diarrhea and abdominal cramps. The two
major types of inflammatory bowel disease are Crohn’s
disease and ulcerative colitis.
Crohn’s disease is a chronic inflammation of the
intestines that is usually confined to the ileum. It is charac-
terized by abdominal cramps or pain, diarrhea (sometimes
bloody), fever, and anorexia. The clinical course may be
erratic, with frequent relapses interspersed with periods of
symptom remission.24
Ulcerative colitis, which is also a chronic inflammatory
disease, is confined to the colon and rectum. Patients with
mild disease may present with fewer than four bowel
movements per day, whereas patients with severe disease
may experience more than six bowel movements per day
along with weight loss, fever, and anemia. While the
diarrhea is often bloody, many patients do not have grossly
bloody stools, even with exacerbations. It too may be
characterized by periods of remission.
A documented history of inflammatory bowel diseasewill aid in providing patients appropriate evaluation and
treatment. Some patients, however, will have episodic
symptoms for years before being correctly diagnosed.
Eliciting a family history of inflammatory bowel disease or
other risk factors for it will allow rapid evaluation of this
condition by referral to a gastroenterologist.24 The diagnosis
rests on the clinical history, stool studies to exclude infec-
tion, and colonoscopy to determine the presence and extent
of disease.
Ischemic Bowel Disease
Ischemic bowel disease should be considered in adults with
abdominal pain, especially if they are older than 50 years or
have a history of peripheral vascular disease. Most patients
with acute mesenteric ischemia will present with severe
abdominal pain, although there can be a paucity of physical
findings. The abdominal pain may be followed by a rapid
and forceful bowel movement.25 Other patients may have
chronic mesenteric ischemia with chronic intermittent
abdominal pain of up to several months’ duration (intestinal
angina) followed by an acute attack of pain. These patients
may experience weight loss, as well as occasional diarrhea
and bloating.26 Occult fecal blood is present in up to 75% of
patients.27 Bloody diarrhea may occur in those with ischemic
colitis (inflammation of the colon caused by insufficient blood flow to the colon); those with small bowel ischemia
will have voluminous diarrhea.28 Individuals at increased
risk for ischemic bowel disease include patients with
Table 2. Agents Causing Infectious Diarrhea And Their Associated Symptoms.
Campylobacter jejuni Symptoms: fever, headache and muscle pain followed by
diarrhea (sometimes bloody), abdominal pain and nausea
that appear 2-5 days after eating; may last 7-10 days.
Clostridium perfringensSymptoms: diarrhea and gas pains may appear 8-24 hours
after eating; usually last about one day, but less severesymptoms may persist for 1-2 weeks.
Escherichia coli 0157:H7Symptoms: diarrhea or bloody diarrhea, abdominal cramps,
nausea, and malaise; can begin 2-5 days after food is eaten,
lasting about eight days. Very young patients can develop
hemolytic uremic syndrome, which causes acute kidney
failure. A similar illness, thrombotic thrombocytopenic
purpura, may occur in older adults.
Listeria monocytogenesSymptoms: fever, chills, headache, backache, sometimes
abdominal pain and diarrhea; onset from 7-30 days after
eating, but most symptoms are reported 48-72 hours after
consumption of contaminated food; primarily affectspregnant women and their fetuses, newborns, the elderly,
people with cancer, and those with impaired immune
systems; can cause fetal and infant death.
Salmonella (many types)Symptoms: stomach pain, diarrhea, nausea, chills, fever, and
headache usually appear 8-72 hours after eating; may last
1-2 days; all age groups are susceptible, but symptoms are
most severe for the elderly, the infirm, and infants.
Shigella (many types)Symptoms: disease referred to as “shigellosis” or bacillary
dysentery. Diarrhea containing blood and mucus, fever,
abdominal cramps, chills, and vomiting; 12-50 hours from
ingestion of bacteria; can last a few days to two weeks.
Staphylococcus aureusSymptoms: severe nausea, abdominal cramps, vomiting, and
diarrhea occur 1-6 hours after eating; recovery within 2-3
days—longer if severe dehydration occurs.
Vibrio parahaemolyticusSymptoms: Diarrhea, abdominal cramps, nausea, vomiting,
headache, fever, and chills; onset four hours to four days
after eating; lasts about 2.5 days.
Cyclospora cayetanensisSymptoms: Nausea, vomiting, loss of appetite, and diarrhea;
onset within two days; lasts one week to two months.
Cryptosporidium parvumSymptoms: Profuse watery diarrhea, abdominal pain, appetite
loss, vomiting, and low-grade fever, onset within 1-12 days.
Giardia lamblia
Symptoms: Sudden onset of explosive watery stools,abdominal cramps, anorexia, nausea, and vomiting; onset
within 1-3 days.
Viral gastroenteritis from Norwalk and Norwalk-like virusesSymptoms: Nausea, vomiting, diarrhea, abdominal pain,
headache, and low-grade fever; onset within 1-2 days; lasts
about 36 hours.
Adapted from: U.S. Food and Drug Administration Center for FoodSafety and Applied Nutrition Web site (http://www.cfsan.fda.gov/~dms/qa-fdb12.html, http://www.cfsan.fda.gov/~dms/unwelcom.html).
-
8/9/2019 Emp Diarrea
5/20
COPYRIGHTEDMA
TERIAL
DONOTPHOTOCOP
YORDISTRIBUTEELECTRON
ICALLYWITHOUTWRITTENC
ONSENTOFEBPRACTICE,LLC
5 Emergency Medicine PracticeJuly 2004 • EMPractice.net
hypovolemia, sepsis, cardiac arrhythmias, congestive heart
failure, and those using vasoconstrictive medications or
drugs (e.g., digitalis, pseudoephedrine, cocaine, amphet-
amines).29 Ischemia may progress to infarct unless detected
and treated early.
Radiation Enteritis
Radiation therapy is used to treat a number of urologic,
gynecologic, and colorectal cancers. During the radiation
treatment period, most patients experience tenesmus,
bleeding, and diarrhea.30 Malabsorption from mucosal
damage and bacterial overgrowth are two factors that
contribute to these symptoms.26 Symptoms can start within
hours of initial treatment and usually resolve two or three
months after treatment cessation,30 although some patients
may develop chronic problems necessitating surgery. The
rectum is the most commonly inflamed site given its
proximity to the irradiated tissue; the terminal ileum can
also be irradiated in patients undergoing treatment for
pelvic malignancies.
Treatment of acute radiation enteritis involves tempo-
rary discontinuation of radiation therapy, selective intrave-nous fluid administration, and antimotility medications.
Sucralfate may ameliorate the symptoms of radiation
enteritis. In one double-blind placebo-controlled trial of
patients with prostate or bladder cancer randomized to
receive either oral sucralfate or placebo, those patients
receiving sucralfate had improvement in the frequency and
consistency of bowel movements, and fewer patients
required treatment with anti-diarrheal preparations.31
Appendicitis
Patients with appendicitis can have vomiting as well as
loose stools. Rectal irritation by an inflamed pelvic appendix
can produce small amounts of watery diarrhea, as com-pared to the voluminous amounts produced as a conse-
quence of gastroenteritis.32 In Rothrock et al’s study of 181
children younger than 13 years who were ultimately found
to have appendicitis, 27% were initially misdiagnosed.
Patients in this group were more likely to be younger, have
vomiting before pain, and have diarrhea (in addition to
constipation, dysuria, and upper respiratory tract symp-
toms).33 A retrospective case series review of 63 children
younger than 3 years ultimately diagnosed with appendici-
tis found that 57% were initially misdiagnosed; diarrhea
was commonly reported.34 A retrospective review of 87
patients with appendicitis revealed that six patients (7%)
required more than one ED visit before their diagnosis wasestablished. The initial diagnosis in two of these patients
was gastroenteritis. These six patients were more likely to
have a normal appetite, to have diarrhea, and to be afe-
brile.35 While most patients with appendicitis present with
right lower quadrant abdominal pain, 15% of appendices
are in atypical locations, causing pain in locations other than
the right lower quadrant.32 Gastroenteritis can present with
fevers higher (>103˚F) than those seen with appendicitis,
and in general, vomiting and diarrhea precede abdominal
pain, whereas vomiting follows abdominal pain in appendi-
citis. Because appendicitis will steadily worsen, while
uncomplicated gastroenteritis generally resolves with fluids,
a period of observation can help identify patients with
appendicitis if the diagnosis is unclear.
Miscellaneous Causes
Many other entities should be considered in the differential
diagnosis of diarrhea, including melena, laxative abuse,
partial bowel obstruction, various malabsorption syn-
dromes (e.g., Whipple’s disease, small bowel bacterial
overgrowth, celiac sprue), food allergy, rectosigmoid
abscess, colon cancer, diverticulitis, hyperthyroidism, and
pernicious anemia. Many medications (as well as herbal
remedies) can cause diarrhea. In pediatric patients, age-
appropriate problems such as intussusception and Meckel’s
diverticulum should be considered in the differential
diagnosis of diarrhea. Uncommon causes of diarrhea
include mushroom poisoning, ciguatera fish poisoning,
arsenic ingestion, and exposure to pesticides, sodium
fluoride, thallium, or zinc. In most of these cases, diarrhea is
part of a symptom complex, and other suggestive elements
of the history are present.
Prehospital Care
Initial prehospital assessment should focus on the patient’s
vital signs and mental status. Transport hemodynamically
stable patients without further intervention. Follow local
EMS protocols for hypotension/shock for patients who are
hemodynamically unstable; usually, this includes establish-
ing at least one large-bore intravenous line and infusing
crystalloid solution and expediting the transport of unstable
patients for further evaluation and care.
While gastrointestinal infections may be caused by a
variety of agents, including bacteria, viruses, and protozoa,
only a few agents have been documented in person-to-person transmission. Generally, adherence to either stan-
dard or contact precautions will minimize the risk of
transmitting enteric pathogens.36
Emergency Department Evaluation
HistoryHistory Of Present Illness
Obtaining a thorough history is crucial. Certain issues
are important to address during patient assessment.
They include:
• Type and volume of stools: Also note whether the
stools contain any blood. (Note that melena may not be perceived by the patient to be “ bloody”; ask about
blackened stools as well. See also the March 2004
issue of Emergency Medicine Practice, “Gastrointestinal
Bleeding: An Evidence-Based ED Approach To
Risk Stratification.”)
• Associated symptoms such as nausea, vomiting,
abdominal pain, fever, and tenesmus: When vomiting
is a prominent feature of the patient’s symptoms,
viruses are the more likely etiologic agents.12,37 Fever
greater than 38.5˚C (101.3˚F) is usually associated with
intestinal inflammation due to invasive bacteria (e.g.,
-
8/9/2019 Emp Diarrea
6/20
COPYRIGHTEDMATERIAL—D
ONOTPHOTOCOPYORDIST
RIBUTEELECTRONICALLYWITHOUTWRITTENCONSENTO
FEBPRACTICE,LLC
Emergency Medicine Practice 6 EMPractice.net • July 2004
Shigella, Salmonella, or Campylobacter species), enteric
viruses, or toxin-induced damage due to Clostridium
difficile or Entamoeba histolytica.37
• Character and location of any abdominal pain: Pain is
common in patients with mesenteric ischemia, inflam-
matory bowel disease, and irritable bowel syndrome.22
• Duration of symptoms: Symptom duration can help
narrow the differential diagnosis. Viral gastroenteritis
usually lasts 12-60 hours.2 Thus, it is less likely that
diarrhea lasting more than a couple of days or so is
viral. Diarrhea lasting greater than two weeks often has
a different etiology (see Table 3) than diarrhea that has
been present for less than two weeks.37
• Weight loss: Determine whether the patient has lost
weight. Patients with diarrhea may have weight loss
because of both increased output and reduced intake.
Substantial weight loss is more likely due to ischemia,
neoplasm, or malabsorptive syndromes.22 Weight loss
may be an indicator of dehydration in children.
• Indicators of dehydration: Asking about urine output,dizziness, thirst, and syncope—as well as asking
family members or prehospital personnel about altered
mental status—is useful in assessing the patient’s
volume status.
• Epidemiological risk factors: Further questions should
focus on the patient’s recent diet, and specifically
whether there has been any ingestion of seafood, raw
or undercooked meat, eggs, or milk products. In
addition, ask about recent foreign travel or local
outings involving lake or stream swimming or visits to
a farm, ill contacts, group living arrangements (e.g.,
nursing home, college dormitory) or day care atten-
dance, and occupational hazards such as food handling
or working with animals.
Past Medical History
The patient’s past medical history also provides essential
information for the management of patients with diarrhea.
Are you treating an otherwise healthy 20-year-old woman, a
patient with HIV/AIDS, or a 70-year-old diabetic man with
a history of congestive heart failure taking numerous
medications? Is the patient undergoing cancer treatment?
Consider pathogens that affect immunosuppressed hosts in
patients receiving chemotherapy. Acute radiation enteritis is
a concern in those who have undergone radiation treatment
within the past six weeks. Inquire about other gastrointesti-
nal ailments such as Crohn’s disease or ulcerative colitis.
Medications
Obtaining a history of medication use—specifically includ-
ing prescription, over-the-counter, and herbal prepara-
tions—is important, since many can cause diarrhea. Some of
the more common offenders include laxatives, antibiotics,
colchicine, and magnesium- or calcium-containing antacids.If there is a history of antibiotic use within the past three
months, C. difficile-induced diarrhea is an important
consideration.38 Diabetics using a relatively new class of
hypoglycemic medications known as alpha-glucosidase
inhibitors (e.g., acarbose, miglitol) may develop abdominal
pain, bloating, and diarrhea. Artificial sweeteners contain-
ing sorbitol or mannitol are poorly absorbed and may cause
diarrhea. Patients on enteral tube feedings may also develop
diarrhea.28 The elderly are more likely to be on multiple
medications and may be more susceptible to adverse effects.
Review Of Systems
A brief review of systems is additionally helpful. Apatient who is currently menstruating may have guaiac-
positive stools secondary to stool sample contamination
from menstrual blood. The patient’s pregnancy status is
important for antibiotic selection, use of medications
for symptomatic treatment of the diarrhea, and decisions
about managing her hemodynamic status. Ask the patient
about the ability to get to the bathroom on time. Some
individuals complain of diarrhea when the real problem
is fecal incontinence.
Social History
The patient’s occupational history may be relevant if they
work as a veterinarian, food handler, or day care center ornursing home employee. The patient’s sexual preference
and whether they engage in receptive anal intercourse
should be ascertained as this may expand the differential
diagnosis to include AIDS-associated diarrhea as well as
proctitis secondary to sexually transmitted diseases.
Inquire about alcohol and drug use. Patients who abuse
alcohol may present with various abdominal complaints,
including diarrhea and melena. Opioid withdrawal
frequently involves nausea, vomiting, and diarrhea. Patients
with eating disorders or those attempting to lose weight
should be questioned about laxative abuse.
Table 3. Common Causes Of DiarrheaPersisting Longer Than Two Weeks.
ParasitesCryptosporidium parvum, Cyclospora cayetanensis, Entam-
oeba histolytica, Giardia lamblia, microsporidia
BacteriaCampylobacter, Clostridium difficile, Escherichia coli, Listeria
monocytogenes, Salmonella enteritidis, Shigella
Viral infectionsHIV
MedicationsAntibiotics, high blood pressure medications, cancer drugs/
radiation therapy
Noninfectious food sourcesFood allergies; certain food additives (sorbitol, fructose, and
others) are also implicated
Other systemic conditionsDiabetes, thyroid and other endocrine diseases; malignan-
cies/tumors; previous surgery of the abdomen or gas-
trointestinal tract; conditions causing reduced blood flow
to the intestine such as ischemic bowel disease
-
8/9/2019 Emp Diarrea
7/20
COPYRIGHTEDMA
TERIAL
DONOTPHOTOCOP
YORDISTRIBUTEELECTRON
ICALLYWITHOUTWRITTENC
ONSENTOFEBPRACTICE,LLC
7 Emergency Medicine PracticeJuly 2004 • EMPractice.net
Physical Examination
Primary Survey
While patients with a chief complaint of diarrhea rarely
present with an imminent life threat, the initial assessment
of any ED patient should include a rapid assessment of
the ABCs. Hypovolemic or septic shock may require
the patient’s airway to be secured and the patient to
be ventilated.
Secondary Survey
A secondary survey allows for further assessment of the
patient’s volume status as well as the presence or absence of
systemic toxicity. Is the patient febrile? Is postural hypoten-
sion present? Are the mucus membranes dry? For infants, is
the anterior fontanelle sunken? Is the pediatric patient
producing any tears when crying? Note the patient’s skin
turgor, jugular venous pressure, capillary refill, and the
presence or absence of sunken eyes. Also, evaluate the
patient’s mental status. Is the patient awake, alert, and able
to answer questions? Is the patient lethargic or completely
unresponsive? Other features of diagnostic significance
include the presence of flushing or rashes on the skin,mouth ulcers, thyroid masses, wheezing, arthritis, heart
murmurs, hepatomegaly or abdominal masses, ascites,
and edema.16
The abdominal examination should include ausculta-
tion of bowel sounds as well as the presence or absence
of tenderness or peritoneal signs. A rectal examination
can determine whether the stools are grossly bloody,
melanotic, or guaiac-positive. Given the fact that melanotic
stools are usually liquid, the patient may refer to this type
of stool simply as “diarrhea.” Thus, a rectal examination
may play an important role in assessing the nature of the
stools. Selected female patients may require a pelvic
examination depending on the degree and location of their abdominal pain.
Diagnostic Studies
Blood Tests
Routine CBC counts or chemistry panels are unnecessary in
most patients since diarrhea is a self-limited problem in
most cases. A chemistry panel may reveal an electrolyte
imbalance or the degree of dehydration in systemically ill
patients, or in those with severe or persistent diarrhea. In
patients with bloody diarrhea, obtain a CBC and platelet
count to exclude hemolytic uremic syndrome. (Hemolytic
uremic syndrome is discussed in further detail in the sectionon pediatric patients later in this article.) Eosinophilia on the
leukocyte differential can point to food allergy, collagen-
vascular diseases, neoplasm, parasitic infections, or eosino-
philic gastroenteritis or colitis.22 Such diagnostic testing
should be reserved for select cases in which clinical or
epidemiologic factors or disease severity suggest their
need.5 Unfortunately, the literature does not provide clear-
cut indications for such testing.
Fecal Leukocyte/Lactoferrin Testing
Fecal leukocytes and fecal lactoferrin testing can provide
more timely results and are therefore more useful in the ED
setting than stool cultures in identifying causes of inflamma-
tory diarrhea. A selective approach to fecal leukocyte/
lactoferrin testing in patients with diarrhea is recom-
mended, yet the precise approach remains a matter of
dispute. Community-acquired or traveler ’s diarrhea,
nosocomial diarrhea, and diarrhea persisting more than
seven days have been suggested by the Infectious Diseases
Society of America as indications for testing.5 The utility of
these tests lies in helping to determine whether antibiotic
treatment is indicated.37
Occult blood, fecal leukocytes, and fecal lactoferrin are
often found in the stools of patients with inflammatory
diarrhea. The most common pathogens in patients with a
positive test result include Shigella, Salmonella, Campylobacter,
Aeromonas, Yersinia, non-cholera Vibrio species,40,41 and
Clostridium difficile.42
Fecal leukocytes are generally seen in the stool of
patients with shigellosis, salmonellosis, Campylobacter,
enteroinvasive E. coli, enterohemorrhagic E. coli, or staphylo-
coccal enterocolitis.43 Other conditions in which fecal
leukocytes may be seen include Entamoeba histolyticaenteritis, Crohn’s disease, ulcerative colitis, and
pseudomembraneous colitis.44
Lactoferrin is a protein found in leukocytes. The fecal
lactoferrin assay can measure levels of lactoferrin released
from damaged or deteriorated leukocytes in stool speci-
mens.43 Although more research is needed, some studies
indicate that fecal lactoferrin is more sensitive than fecal
leukocytes or occult blood as a screening tool for detecting
invasive pathogens45,46 as well as for detecting other causes
of inflammatory diarrhea such as ulcerative colitis and
Crohn’s disease.47,48 The test is slightly costlier than fecal
leukocyte testing, but it is quicker and easier to perform and
is not limited by the need for a fresh stool specimen.49Guaiac-positive stools, as well as the findings of fecal
leukocytes and fecal lactoferrin, are all predictive of finding
an identifiable bacterial pathogen on stool culture.37 In one
prospective study of 873 patients, stool cultures were
ordered in 549 episodes (62.6%), most frequently for patients
with fever, more than 10 stools per day, or visibly bloody
stools. Enteropathogens were identified in 168 episodes
(30.6%).39 In another well-designed study of 1040 patients,
the absence of occult blood in the stool was a reliable
indicator for a lack of enteroinvasive bacteria.40
Stool Culture
While readily obtainable tests such as heme- or leukocyte-positive stools can provide the ED practitioner with
valuable information, stool cultures may be advisable under
certain circumstances.
The use of antibiotics in certain cases of bacterial
diarrhea can produce undesirable outcomes, so determining
the causative agent via stool cultures can be helpful.
For instance, treatment of salmonellosis can prolong the
carrier state and lead to a higher clinical relapse rate. 28
The likelihood of hemolytic uremic syndrome in patients
infected with E. coli 0157:H7 is increased with the use of
antibiotics.50 Empiric antibiotic use may increase the risk
-
8/9/2019 Emp Diarrea
8/20
COPYRIGHTEDMATERIAL—D
ONOTPHOTOCOPYORDIST
RIBUTEELECTRONICALLYWITHOUTWRITTENCONSENTO
FEBPRACTICE,LLC
Emergency Medicine Practice 8 EMPractice.net • July 2004
of C. difficile colitis.
Determination of antimicrobial susceptibility is also
important given the emergence of resistance to some
commonly used antibiotics. Finally, negative stool culture
results may be important prerequisites for the diagnosis of
certain ailments such as inflammatory bowel disease.
Stool cultures can also play a role in identifying agents
that have significant public health consequences. An
outbreak of illness due to Salmonella enteritidis serves to
illustrate this point. The state public health laboratory in
Minnesota received a higher-than-expected number of
reports of Salmonella isolates from local clinical laboratories
in 1994. These reports ultimately led to the detection of a
nationwide outbreak of Salmonella enteritidis infection due to
contaminated ice cream that had been widely distributed
(with patients afflicted in 41 states). An estimated 220,000
people were affected by this outbreak.51 Elimination of the
contaminated product from the market potentially pre-
vented the spread of this infection to thousands of others.
These preventive measures were possible because stool
cultures were obtained on the first patients who presented
to their physicians with diarrhea.While these examples provide compelling evidence for
obtaining stool cultures on patients with diarrhea, the yield
on routinely obtained stool cultures is low. In six studies
conducted between 1980 and 1997, stool cultures were
positive in 1.5%-5.6% of cases.5 This translates to a cost of
$952-$1200 for each positive culture obtained. Interestingly,
in the study with a positive culture yield of 5.6%, 63% of the
patients had grossly bloody stools, while 91% presented
with a history of bloody diarrhea.52
Therefore, experts recommend restricting the use of
stool cultures. In patients in whom vomiting is a prominent
feature of their disease, viral agents are the likely etiology
and stool cultures will have a low yield. Proposed criteriathat suggest a higher yield from stool cultures include
history of bloody stools (grossly bloody or heme-positive
stools) or stools containing leukocytes or lactoferrin;
immunocompromised patients; fever higher than 38.5˚C
(101.3˚F); systemic illness or an illness that is clinically
severe or persistent; and patients with severe abdominal
pain.2,28,53 Selective cultures can be considered in specific
circumstances such as bloody diarrhea in afebrile patients
with a history of ingestion of unpasteurized juice or milk or
undercooked beef (suggests enterohemorrhagic E. coli);
patients who have consumed shellfish within 72 hours of
the onset of illness (suggests Vibrio parahemolyticus); and
patients who have been on antibiotics within the past three
months (suggests C. difficile).
Ideally, stool samples should be sent for culture within
two hours after passage to allow for detection of certain
pathogens that perish quickly. If the patient is unable to
provide a stool sample, a rectal swab can be brought to the
lab in transport media and then cultured.28
Routine stool cultures in most laboratories will identify
Shigella, Campylobacter, and Salmonella.2 (In patients who
develop diarrhea after three days of hospitalization, C.
difficile testing will have a higher yield (15%-20%), whereas
standard stool cultures will have poor yields.28)
Stool Testing For Parasites
In developed countries, testing for ova and parasites in
patients with acute diarrhea is rarely indicated.54 Cases in
which testing for ova and parasites may be appropriate
include patients who present with diarrhea lasting more
than 14 days, the immunocompromised, and patients who
have not responded to antimicrobial therapy.2 Other
situations in which to consider ova and parasite testing
include a community outbreak of diarrhea with a suspectedwaterborne cause, exposure to infants at a day care center,
patients with a history of travel to endemic areas such as
Russia (Giardia, Cryptosporidium), Nepal (Cyclospora), or
mountainous regions of North America (Giardia). In patients
with chronic bloody diarrhea and a paucity of fecal leuko-
cytes, consider amebiasis.5 As with routine stool cultures,
stool culture for ova and parasites in patients in whom
diarrhea develops three or more days after hospitalization
has an extremely low yield.49
Endoscopy/Computed Tomography
Lower gastrointestinal endoscopy should be considered in
patients with rectal bleeding, severe abdominal pain, fever,as well as negative stool tests for pathogens or otherwise
unexplained chronic diarrhea lasting longer than three
weeks.20 Biopsy and evaluation of the colonic mucosa is
crucial to exclude the presence of C. difficile
pseudomembraneous colitis, inflammatory bowel disease,
ischemic colitis, microscopic or collagenous colitis (types of
inflammatory bowel disease), and malignancy.20 In one
study, 809 HIV-negative patients with chronic non-bloody
diarrhea underwent colonoscopy. Fifteen percent of these
patients had an inflammatory cause of diarrhea, including
microscopic colitis and, to a lesser extent, Crohn’s disease
and ulcerative colitis.55
Key Points In The Management Of Patients With Diarrhea
• For most patients, diarrheal illness is short and self-limited.
• While the presence of abdominal discomfort and loose stools
can be consistent with gastroenteritis, this symptom complex
may also signal appendicitis, ischemic bowel disease,
inflammatory bowel disease, radiation enteritis, irritable bowel
syndrome, and a wide variety of other disorders.
• Correct diagnosis of an acute diarrheal illness is largely
dependent on a complete history and physical examination
rather than on extensive, costly laboratory testing.
• Treatment for many forms of diarrhea consists of
rehydration and symptomatic relief.
• Pediatric, elderly, chronically ill, or immunocompromised
patients are at greatest risk for serious etiologies and/or
complications, including dehydration.
-
8/9/2019 Emp Diarrea
9/20
COPYRIGHTEDMA
TERIAL
DONOTPHOTOCOP
YORDISTRIBUTEELECTRON
ICALLYWITHOUTWRITTENC
ONSENTOFEBPRACTICE,LLC
9 Emergency Medicine PracticeJuly 2004 • EMPractice.net
In patients with unexplained diarrhea and a negative
colonoscopic examination, upper gastrointestinal tract
infections (Giardia, bacterial overgrowth syndrome)
and small bowel and pancreatic diseases resulting in
malabsorption should be considered. Biopsies obtained by
upper endoscopy can determine etiologies such as celiac
sprue (which causes the malabsorption of gluten),
Whipple’s disease (a malabsorption illness caused by
Tropheryma whippelii), or other malabsorptive syndromes.
CT scanning of the abdomen and pelvis may provide
further information about small bowel and colonic disease
or extrinsic disease processes such as pancreatic tumors
that can cause diarrhea.56
Although these are not primary diagnostic consider-
ations, a working knowledge of these options is important
to facilitate the work-up of patients who present to the ED
with persistent diarrhea and a negative initial evaluation.
Treatment
Treatment decisions are influenced by several factors,
including the patient’s hydration status, the need for
symptomatic relief, and the likelihood of the presence of a
bacterial pathogen.
Rehydration
Rehydration can be accomplished by oral or intravenous
fluid administration. In patients with moderate-to-severe
dehydration, as well as those in whom vomiting disallows
adequate oral fluid intake, intravenous hydration speeds up
the recovery process. In many cases, rehydration can be
achieved with oral rehydration solutions. Fluids used for
rehydration should contain sodium, potassium, and
glucose.28 Various commercial types of oral rehydration
solutions (such as Pedialyte, Lytren, and Rehydrolyte) areavailable. Various home preparations have been proposed,
although they are not recommended in children. Addition-
ally, sports drinks, which are designed to replenish fluids
and electrolytes lost by sweating, are inadequate to replace
diarrheal sodium losses. These solutions can be effective if
they are supplemented with another source of salt such as
pretzels or crackers.16,22
The use of the “BRAT” diet (bananas, rice, applesauce,
toast) is commonly recommended, although evidence-based
data supporting its use are sparse. One evidence-based
clinical practice guideline suggests that continued use of the
patient’s preferred, usual, and age-appropriate diet should
be encouraged, and that the BRAT diet offers no advantageunless those foods are part of the usual diet.4
Symptomatic Therapy
Symptomatic therapy may be used in selected patients with
diarrhea. Patients who are afebrile and have non-bloody
diarrhea as well as most patients with chronic diarrhea
associated with inflammatory bowel disease may benefit
from the use of antimotility agents.28 Antimotility agents
should generally be avoided in patients with high fever,
sepsis, immunocompromise, bloody diarrhea, or suspected
inflammatory diarrhea because of delayed clearance of
enteric pathogens, prolonged fever, and toxic megacolon,28,53
although some argue that antimotility agents may be
used in patients with nondysenteric forms of diarrhea
caused by enteroinvasive pathogens as long as antibiotics
are also prescribed.
Agents available for diarrhea relief include loperamide,
diphenoxylate, and bismuth subsalicylate.
Loperamide is a commonly recommended antimotility
agent because of its safety and efficacy profile. It slows
intraluminal flow of liquid by inhibiting peristalsis, which
allows for increased intestinal absorption of fluid and
electrolytes, which in turn results in substantial stool
volume reduction. When used with antibiotics in patients
with traveler’s diarrhea or bacillary dysentery, loperamide
can reduce the duration of diarrhea by one day.53 It is an
opiate that does not penetrate the nervous system; thus,
there are no CNS side-effects or potential for addiction.
Diphenoxylate is less costly than loperamide; however,
it is chemically related to meperidine, can penetrate the
CNS, and may be habit-forming.
Bismuth subsalicylate helps alleviate symptoms of
dyspepsia, nausea, and diarrhea. It exerts its anti-diarrhealeffects via an antisecretory mechanism, binding of bacterial
toxins, and by its inherent antimicrobial activity. It helps
alleviate nausea and vomiting by a topical effect on the
gastric mucosa and is preferred when vomiting is a promi-
nent complaint. It has been used effectively in children with
diarrhea as well as in patients with traveler ’s diarrhea.57
Empiric Antibiotic Therapy
Authorities disagree on the indications for empiric antibiotic
therapy in diarrheal illness. When effective, antibiotics
shorten the course of an acute diarrheal illness by one
or two days. This potential benefit should be balanced
against the risk of drug-induced side-effects. The expenseof therapy and the broader societal issue of antibiotic
resistance induced by antibiotic overuse should also
be considered.5
Interestingly, although physicians often believe that
patients expect antibiotics for a variety of ailments, one
study found that patient satisfaction with medical care in
the case of diarrheal illness correlates poorly with receiving
antibiotics. An additional finding of this same study is that
physicians are not adept at identifying which patients
expect antibiotics.58
Empiric antibiotics should be considered for patients
with acute dysentery or those with moderate-to-severe
traveler’s diarrhea.5 Diarrhea lasting longer than two totwo-and-a-half days has a higher probability of having a
non-viral cause; thus, empiric antibiotics can be given in
these cases as well. Other criteria for empiric antibiotic
therapy include fever greater than 38.5˚C (101.3˚F) plus
either leukocyte-, lactoferrin-, or hemoccult-positive stools.28
Table 4 on page 13 lists the pharmaceutical regimens
recommended for patients with diarrheal illnesses. In most
instances, fluoroquinolones for adults and trimethoprim-
sulfamethoxazole (TMP-SMX) for children are reasonable
Continued on page 13
-
8/9/2019 Emp Diarrea
10/20
COPYRIGHTEDMATERIAL—D
ONOTPHOTOCOPYORDIST
RIBUTEELECTRONICALLYWITHOUTWRITTENCONSENTO
FEBPRACTICE,LLC
Emergency Medicine Practice 10 EMPractice.net • July 2004
The evidence for recommendations is graded using the following scale. For complete definitions, see back page. Class I: Definitelyrecommended. Definitive, excellent evidence provides support. Class II: Acceptable and useful. Good evidence provides support. Class III:
May be acceptable, possibly useful. Fair-to-good evidence provides support. Indeterminate: Continuing area of research.
This clinical pathway is intended to supplement, rather than substitute for, professional judgment and may be changed depending
upon a patient ’ s individual needs. Failure to comply with this pathway does not represent a breach of the standard of care.
Copyright ©2004 EB Practice, LLC. 1-800-249-5770. No part of this publication may be reproduced in any formatwithout written consent of EB Practice, LLC.
Clinical Pathway: Approach To Patients With Diarrhea
Is the patient stable?
➤ ➤
History and physical examination
(Class I)
ABCs, resuscitate, then history and
physical examination (Class I)
YES NO
Provide symptomatic therapy• Rehydration (IV or oral) (Class I)
• Antiemetics as needed (Class II)
• Antipyretics as needed (Class II)
• Antibiotics as indicated (Class II)
• Antimotility agents as indicated (Class II)
• Other symptomatic relief as needed (Class II)
➤ ➤
➤
Diagnostic evaluation as indicated
Potentially serious diagnosis
possible, or patient too ill
to discharge
Acute, self-limited process likely
➤ ➤
Patient too ill to dischargeDiagnosis clear
and stable clinical state
Consult and/or admit (Class I) Consult and/or admit (Class II) Discharge (Class I)
➤ ➤
➤ ➤ ➤
-
8/9/2019 Emp Diarrea
11/20
COPYRIGHTEDMA
TERIAL
DONOTPHOTOCOP
YORDISTRIBUTEELECTRON
ICALLYWITHOUTWRITTENC
ONSENTOFEBPRACTICE,LLC
11 Emergency Medicine PracticeJuly 2004 • EMPractice.net
Sample Discharge Instructions For Patients With Diarrhea
Diarrhea (loose, watery bowel movements) is often caused by an infection. Many infections that cause diarrhea
simply go away by themselves. Diarrhea can also be caused by other things, like medications, bleeding into the
stomach or bowels, diseases of the bowels, appendicitis, and many others. Diarrhea can happen by itself or may
happen with other symptoms, like cramps or pain in the stomach and bowel area, fever, vomiting, rash, or bleeding
from the rear end. You can become dehydrated (lose too much water) because of diarrhea.
Adults
Signs of dehydration
• You are very thirsty
• You feel weak or dizzy
• You faint or feel like you might faint
• Your skin is dry or very loose
• Your urine is dark
How to avoid or treat dehydration
For the first 1-2 days: Drink lots of fluids, such as
caffeine-free sodas, sports drinks, and flavoredmineral water, or an oral rehydration solution that you
can buy at the supermarket or pharmacy. Nibble on
salted crackers or pretzels (you need the salt) and
drink some orange juice or eat some bananas (for the
potassium, needed for the heart and muscles. You are
probably drinking enough if you are not thirsty and
your urine is pale yellow.
After the first 1-2 days: Try plain potatoes,
noodles, rice, boiled cereals, bread, and other similar
items. Go back to your regular diet if the diarrhea
is gone.
Do Not:
• Don’t drink milk or eat dairy products (cheese, ice
cream) for 2-3 days
• Don’t drink caffeine (tea, cola, coffee)
• Don’t drink alcohol
• Don’t drink fruit juices like prune, apple, or grape
juice (these can cause diarrhea)
Children
Signs of dehydration
• Your child is very thirsty
• Your child is very weak, sleepy, or cranky
• Your child’s skin feels cool, doughy, or loose
• Your child cries but does not make tears
• Your child does not make as much urine as usual
How to avoid or treat dehydration
Use an oral rehydration solution that you can buy
at the pharmacy or supermarket. Let your child eat a
regular diet as soon as possible. If your child is
vomiting, try having him or her drink very small
amounts of liquid until the vomiting stops.
Do Not:
• Don’t use water or sports drinks for your
dehydrated child (use an oral rehydration
solution instead)
• Don’t withhold dairy products (milk, cheese, ice
cream) from your child
• Don’t have your child drink fruit juices like prune,apple, or grape juice (these can cause diarrhea)
Medications
Use all medications exactly as your doctor advises.
You have been prescribed:
• ______________________________
• ______________________________
• ______________________________
You may also use:
• ______________________________
• ______________________________
• ______________________________
Reasons to return to the EmergencyDepartment:
• You are dehydrated
• You are vomiting and cannot eat or drink
• You have a fever over _____˚ F ( _____˚ C )
• You have blood, pus, or mucus in your diarrhea or
bowel movements
• You have pain in the stomach or bowel area
• You have bloody, black, or wine-colored diarrhea
or bowel movements
• Your sickness lasts more than _____ days
• You are not getting better at home
• You have any other problems that concern you
See your own doctor in _____ days.
Copyright ©2004 EB Practice, LLC. 1-800-249-5770. No part of this publication may be reproduced in any formatwithout written consent of EB Practice, LLC.
-
8/9/2019 Emp Diarrea
12/20
COPYRIGHTEDMATERIAL—D
ONOTPHOTOCOPYORDIST
RIBUTEELECTRONICALLYWITHOUTWRITTENCONSENTO
FEBPRACTICE,LLC
Emergency Medicine Practice 12 EMPractice.net • July 2004
Ten Pitfalls To Avoid
1. “The patient had nausea, vomiting, and diarrhea—typical
gastroenteritis, right?”
While that’s often the case, a more thorough evaluation is
required. Gastrointestinal symptoms are notoriously non-
specific. Plus, a wide variety of extra-abdominal conditions
can present with abdominal complaints (diabeticketoacidosis, thyrotoxicosis, poisonings, pneumonia).
2. “The patient had nausea, vomiting, and diarrhea. I
diagnosed ‘viral gastroenteritis’ and discharged her in
stable condition. She never told me that she recently
returned from an overseas trip!”
Travelers, patients recently discharged from the hospital,
patients with recent medication use (especially antibiotics),
and the immunocompromised are susceptible to a much
wider range of etiologies. Inquire routinely about these
aspects of their medical history. Patients often do not
realize the significance of these factors.
3. “The patient reported diarrhea. He didn’t tell me his stool
was black! How was I supposed to know that he had a
gastrointestinal bleed?”
Many patients either don’t know the characteristics of the
stool they’re passing or fail to recognize the significance of
various abnormalities (blood, mucus, melena). Ask the
patient for specifics, and if any doubt remains about what is
being passed, do a rectal examination.
4. “The patient had nausea, vomiting, and diarrhea—typical
gastroenteritis. How was I supposed to know it was
appendicitis?” (Part 1)
Unfortunately, there are no absolute guidelines. While
appendicitis remains a primarily clinical diagnosis,
quantifying might help. Appendicitis patients tend to have
one or two emesis episodes after their abdominal pain
begins, and they typically pass one or two loose stools.
Those with gastroenteritis, on the other hand, tend to have
multiple episodes of vomiting and voluminous loose stools.
5. “The patient had nausea, vomiting, and diarrhea—typical
gastroenteritis. How was I supposed to know it was
appendicitis?” (Part 2)
Serial abdominal examinations can be extremely helpful
in identifying appendicitis. Patients with gastroenteritis
generally improve with time and fluids. While the pulse
and blood pressure of patients with appendicitis may
improve with intravenous fluids, abdominal signs andsymptoms like localized tenderness, guarding, and
rebound typically persist.
6. “The patient had nausea, vomiting, and diarrhea, but was
otherwise unremarkable. I diagnosed ‘viral gastroenteritis’
and discharged her in stable condition. I had to diagnose
something, right? Too bad she got worse and had to return
to the ED a couple of days later.”
Many entities seem like viral gastroenteritis that aren’t. If
the diagnosis is unclear, stick to the facts and write
“vomiting and diarrhea with dehydration” (or something
similar) on the chart. Don’t paint yourself into a corner with
a diagnosis of viral gastroenteritis, which is often a
wastebasket category and implies premature closure of the
diagnostic thought process.
7. “In the ED, everybody with vomiting and diarrhea looks
sick at first—but if they look better after rehydration, it’susually okay to discharge them. This 65-year-old man
looked pretty good after he was rehydrated. How was I
supposed to know that he’d get worse at home? We can’t
admit everyone.”
It seems prudent to be more concerned about those
at the extremes of age (the pediatric and geriatric set),
immunocompromised individuals, and those with
severe abdominal pain. Severe abdominal pain is not
typically associated with gastroenteritis or most common
enteric pathogens.
Loose stools may also be present in patients with
ischemic bowel disease. Consider this diagnosis in the
elderly and in those with a history of vascular disease.
C. difficile-associated diarrhea is a consideration in
anyone who has been taking antibiotics during the past
three months. Certain antibiotics (e.g., clindamycin) place
the patient at particularly high risk for toxin-induced colitis.
8. “I didn’t give Mr. Jones an antimotility drug because I was
always taught it might make the patient worse. I never
expected him to become so dehydrated that he’d pass out!”
While it’s true that there are cases in which antimotility
drugs are contraindicated, they can be of significant benefit
for both comfort and for preventing dehydration in most
adults with diarrhea.
9. “When I discharged Mrs. Smith, she was stable, taking
oral fluids, and had no abdominal pain—but later she
came back in shock, severely dehydrated. What could I
have done differently?”
Written discharge instructions that the patient and her
family can understand and use are critically important. Key
reasons to return to the ED include profuse diarrhea,
dehydration (manifested by weakness, lethargy, altered
mental status, syncope/near-syncope, thirst, decreased
urine output), sustained fever, severe or persistent
abdominal pain, bloody or mucoid stools, and the inability
to take and retain oral fluids. (See also the “Sample
Discharge Instructions For Patients With Diarrhea” on page
11.) Instructions must be clear and specific.
10. “I know that diarrhea can occasionally have serious
sequelae, but it simply isn’t practical to send everyone
for follow-up!”
That’s true, but be careful. In general, otherwise healthy
patients whose symptoms resolve quickly do not require
follow-up. But certain subsets of patients—such as those
with chronic symptoms, the elderly, the very young, the
immunocompromised, and those with co-morbid
illnesses—should be referred for follow-up. And, as
mentioned in the prior item, discharge instructions should
be very clear about circumstances under which patients
should seek further medical care.
-
8/9/2019 Emp Diarrea
13/20
COPYRIGHTEDMA
TERIAL
DONOTPHOTOCOP
YORDISTRIBUTEELECTRON
ICALLYWITHOUTWRITTENC
ONSENTOFEBPRACTICE,LLC
13 Emergency Medicine PracticeJuly 2004 • EMPractice.net
choices.5 Empiric therapy with metronidazole (or other
anti-Giardia agent) can also be considered in patients
with diarrhea lasting 2-4 weeks, without systemic symp-
toms or dysentery.16
In suspected cases of C. difficile-associated diarrhea,
the offending antibiotic should be stopped if possible
and treatment with oral metronidazole begun. Metronida-
zole should be stopped if the assay for C. difficile toxin
is negative.14
When empiric antibiotic therapy is not employed
judiciously, it can be ineffective or even harmful. If vomiting
is a prominent symptom of the illness, a viral source is more
likely. Antibiotics should also not be used if the diarrhea is
thought to be due to Shiga toxin-producing E. coli. This
decision will involve physician judgment since no diagnos-
tic test will yield an immediate result to help the clinician.
Keep in mind that Shiga toxin-producing E. coli (E. coli
0157:H7 being the most common type) causes bloody
diarrhea. E. coli 0157:H7 outbreaks have been associated
with undercooked ground beef as well as with fresh
produce such as unpasteurized apple cider, cabbage, and
alfalfa sprouts.2
Traveler’s Diarrhea
Antibiotics commonly used in the treatment of traveler’s
diarrhea include quinolones, TMP-SMX, as well as nonab-
sorbable or poorly absorbed antibiotics such as rifaximin
and aztreonam.59,60 A comparison of two different doses of
TMP-SMX with or without loperamide vs. loperamide alone
in American adults with acute diarrhea in Mexico revealed
that combination therapy with TMP-SMX and loperamide
was the most efficacious regimen.61
Several studies have also provided data regarding the
efficacy and safety of rifaximin for the treatment of
traveler’s diarrhea. Adults with acute traveler’s diarrhea
who took rifaximin vs. placebo for three days had earlier
resolution of symptoms (average, slightly more than one
day).62 A randomized, controlled trial comparing rifaximin
with TMP-SMX revealed an 11% clinical failure rate with
rifaximin vs. a 29% clinical failure rate with TMP-SMX.63 In
another comparison of rifaximin with ciprofloxacin, no
significant differences were noted between the two treat-
ment groups.59
There is an increasing emergence of fluoroquinolone-
resistant Campylobacter, with the rate of resistance exceeding
80% in Southern Asia.53 For patients with travel histories
to this part of the world, erythromycin or azithromycinare alternatives.53
Prevention Of Traveler’s Diarrhea
Advising patients on ways to minimize the risk of traveler ’s
diarrhea for future trips may be helpful, as well. Beverages
should be carbonated or steaming hot. Uncarbonated
water, bottled water, and even ice may be unsafe. Dry
foods (bread), acidic foods (citrus), and foods with high
sugar content (jellies, syrups) are safe. Buffet items and
green, leafy vegetables (which are washed in water)
should be avoided.57
Advise travelers to take along loperamide or bismuth
subsalicylate as well as an antibiotic. (However, note thatsulfa-based medications can produce photosensitivity.)
One randomized, controlled comparison of bismuth
subsalicylate with loperamide showed similar efficacy;
however, the loperamide group passed fewer stools than
the bismuth subsalicylate group.64 On the other hand,
bismuth subsalicylate has the additional advantage of
alleviating nausea and vomiting and has been shown to
prevent traveler’s diarrhea. In a randomized, double-blind,
placebo-controlled trial, diarrhea developed in 23% of
students receiving bismuth subsalicylate compared with
61% of students taking a placebo. The treatment group
experienced fewer intestinal complaints and were less likely
to pass loose or watery stools. In subjects in whom diarrheadid occur, enteropathogens were identified less commonly
in the treatment group (33%) compared to the placebo
group (71%).57
Special Circumstances
Immunocompromized Patients
Patients with HIV/AIDS are especially prone to diarrheal
illnesses. About half of North American AIDS patients will
develop diarrhea at some point in their illness. The inci-
dence of diarrhea in AIDS patients throughout the develop-
Continued from page 9
Table 4. Empiric Antibiotic TherapyRegimens For Suspected InfectiousDiarrhea.
1. Temperature greater than 38.5˚C (101.3˚F) and oneof the following:
• Guaiac-positive stools or presence of fecal leukocytes or
fecal lactoferrin• Also, consider empiric antibiotics in patients with
diarrhea lasting longer than 48 hours
Treatment:• A fluoroquinolone in adults
• Trimethoprim-sulfamethoxazole in children
Treatment period: 1-5 days
2. Moderate-to-severe traveler’s diarrheaTreatment:
• A fluoroquinolone in adults
• Trimethoprim-sulfamethoxazole in children
Treatment period: 1-5 days
3. Diarrhea for 2-4 weeks without systemic symptomsor dysentery
Treatment:• Consider a seven- to 10-day course of metronidazole or
other anti-Giardia agent
4. Nosocomial diarrheaTreatment:
• Stop the suspected offending antibiotic
• Metronidazole (first line) or vancomycin (in case of
metronidazole failure or when metronidazole is
contraindicated or not tolerated)
Treatment period: 10 days if assay for C. difficile is positive.
Stop antibiotic if assay for C. difficile is negative.
-
8/9/2019 Emp Diarrea
14/20
COPYRIGHTEDMATERIAL—D
ONOTPHOTOCOPYORDIST
RIBUTEELECTRONICALLYWITHOUTWRITTENCONSENTO
FEBPRACTICE,LLC
Emergency Medicine Practice 14 EMPractice.net • July 2004
ing world approaches 100%.65
While HIV/AIDS patients are at risk for all of the
diarrheal ailments that afflict the immunocompetent
population, they can develop enteric infections from a
variety of unusual viral, parasitic, protozoal, and bacterial
organisms. Malignancies affecting the gastrointestinal tract,
such as lymphoma and Kaposi’s sarcoma, may produce
diarrhea, as can many antiretroviral medications.65,66 Finally,
many AIDS patients receive multiple or sustained courses of
antibiotics, predisposing them to C. difficile-associated
diarrhea.66 Therefore, it is important to maintain a broad
differential diagnosis, consider a more aggressive diagnostic
strategy, involve consultants early when appropriate, and
consider hospitalization to improve diagnostic certainty
through a combination of testing, observation, and consult-
ant involvement. (See also the January 2002 issue of
Emergency Medicine Practice, “HIV-Related Illnesses: The
Challenge Of ED Management.”)
Because certain symptoms may suggest particular
organisms (see Table 5), the approach to the HIV/AIDS
patient with diarrhea begins with the history. Definitive
diagnosis, however, is likely to result from either microbio-logical studies or endoscopy.65,66 Begin by assessing the
patient’s immune status. Ask about specific exposures
(sexual practices, travel history, and medications including
recent antibiotics). Inquire also about the stool characteris-
tics (bloody, mucoid, watery) and all associated symptoms
(e.g., fever, vomiting, abdominal pain or cramping, tenes-
mus, bloating, weight loss).65,66 What may seem like an acute
bout of diarrhea may actually represent the beginning of
chronic symptoms. Routine laboratory tests should be
ordered based on the clinical situation.65 Many authorities
recommend that in AIDS patients, a stool culture should be
done, along with C. difficile toxin and ova and parasite
testing.66 If these studies are negative, referral to a gastroen-terologist for endoscopic investigations could be the next
step in the patient’s evaluation.65,66 In the AIDS patient with
chronic diarrhea and a negative microbiological work-up for
infectious agents, authorities are divided on the best
approach. Some advocate symptomatic care, some a course
of empiric antibiotics, and still others suggest endoscopy
with gastrointestinal mucosal biopsy; symptoms and
disease stage guide these decisions.17 Endoscopy often
produces a definitive diagnosis in AIDS patients with
chronic diarrhea and negative stool studies.67
ED treatment options include rehydration, antimotility
agents, and empiric antibiotics, as discussed earlier in this
article. Consultation or referral to the patient’s primary care
provider or infectious disease specialist regarding antibiotic
therapy or changes in antiretroviral therapy are advisable.
Elderly Patients
Diarrheal illnesses are important causes of death and
disability in the elderly. Not only are more serious etiologies
more common in the elderly, the physiological stresses of
diarrheal illness are more challenging for this population.
Age-related declines in immune system functioning,
physiologic changes of aging, medications (e.g., those that
inhibit gastric acid secretion, antibiotics, vasoconstrictors,
and others), and environmental factors (e.g., group living in
nursing homes) all contribute to the elderly patient’s
susceptibility to develop diarrhea.68
Furthermore, elderly patients with diarrhea are often
profoundly dehydrated due to fluid losses associated withtheir illness, fever, an age-related disordered thirst mecha-
nism, co-existing illnesses (e.g., diabetes mellitus), medica-
tions (e.g., diuretics) and limited access to fluids due to
infirmity. Prompt, adequate rehydration is essential;
however, intravenous rehydration of the elderly individual
may be complicated by the presence of cardiovascular
disease or renal dysfunction, thus limiting rapid, large-
volume fluid administration.68
Ischemic colitis, diverticulitis, bacterial overgrowth,
and colonic malignancies are all more common in the
elderly and may present with loose stool.7,68,69 Infections—
notably, C. difficile, E. coli 0157:H7 and Salmonella species—
are more common in the elderly.68,70 Infectious diarrhea inthe elderly is associated with a higher mortality rate.68
If medications are indicated for an elderly patient with
diarrhea, be aware of drug interactions and side-effects,
particularly if the patient is already on multiple medica-
tions. Antacids may reduce the potency of fluoroquinolones.
Additionally, fluoroquinolones can increase theophylline
and warfarin levels and can either increase or decrease
phenytoin levels. Metronidazole can cause nausea and
vomiting, exacerbating the situation for a patient who
initially presented with a gastrointestinal complaint.
Drinking alcohol while taking metronidazole must be
strictly avoided since a disulfiram-like reaction can ensue.
Also, warfarin, phenytoin, and phenobarbital metabolismmay all increase in the patient on metronidazole, potentiat-
ing their effect.68
Be particularly cautious when evaluating elderly
patients with diarrhea combined with abdominal pain.
Elderly patients with abdominal pain tend to have more
serious, often surgical, illnesses that present atypically
or go unrecognized longer.69 (See also the premier issue
of Emergency Medicine Practice, “Assessing Abdominal
Pain In Adults: A Rational, Cost-Effective, And Evidence-
Based Strategy.”) Specific surgical diagnoses to consider
Table 5. Diarrheal Syndromes In PatientsWith HIV/AIDS.
Abdominal cramps, bloating, nauseaPossible agents: Cryptosporidia, microsporidia, isospora,
giardia, cyclospora, and Mycobacterium avium complex
Profuse watery diarrhea, weight loss, electrolytedisturbance (especially in advanced disease)
Possible agent: Cryptosporidia
Bloody stools, fever, abdominal crampsPossible agents: Invasive bacteria, C. difficile,
cytomegalovirus
Adapted from: Sax PE. Opportunistic infections in HIV disease: downbut not out. Infect Dis Clin North Am 2001;15(2):433-55.
-
8/9/2019 Emp Diarrea
15/20
COPYRIGHTEDMA
TERIAL
DONOTPHOTOCOP
YORDISTRIBUTEELECTRON
ICALLYWITHOUTWRITTENC
ONSENTOFEBPRACTICE,LLC
15 Emergency Medicine PracticeJuly 2004 • EMPractice.net
in the elderly patient with diarrhea include bowel
obstruction, appendicitis, mesenteric ischemia, neoplasm,
and diverticulitis.69
Pediatric Patients
Diarrhea is very common in children, especially among
those who attend day care. While most children in devel-
oped nations have mild, self-limited disease, pediatric
patients are susceptible to more adverse outcomes—
especially dehydration—than their healthy adult counter-
parts.21 In the United States, about 9% of all hospitalizations
of children younger than 5 years are because of diarrhea.71
While pediatric patients are susceptible to more
adverse outcomes from diarrheal illnesses, the approach is
generally the same. As with adults, infectious causes
predominate, although children have more of a predisposi-
tion to rotavirus. Another common non-infectious cause in
children is the excessive consumption of sugary, clear
liquids, which can cause copious, watery stools. The wary
practitioner should also keep more serious diagnoses such
as intussusception and Meckel’s diverticulum in mind.
In most cases, prevention of dehydration is the primaryconsideration. Oral rehydration methods are preferred.
After rehydration, recommend prompt resumption of a
regular diet, supplemented with oral rehydration solution
as tolerated. In vomiting children, frequent, small-volume
oral intake is recommended.4
In children, as a general rule, pharmacologic agents
should not be used to treat acute diarrhea.21 While some
well-designed studies have shown statistically significant
results for certain agents, the results were not clinically
significant, and published evidence-based guidelines do not
support their use in children.4,21 Antibiotic use may be
considered in patients in high-risk categories or with serious
bacterial infections.4
Hemolytic uremic syndrome is a complication of E. coli
0157:H7 infection that occurs primarily in children. While
rare, it is the most common cause of acute kidney failure in
infants and children. Early symptoms include vomiting and
diarrhea (sometimes bloody), fever, and irritability or
lethargy. Later, urine output, decreased consciousness,
pallor, bruising, petechiae, or jaundice may occur. An
enlarged liver or spleen may be present. Laboratory studies
will show evidence of hemolytic anemia and acute renal
failure. Administration of packed red blood cells may be
necessary, and severe cases may require dialysis. Neverthe-less, most children receiving treatment recover completely
with no long-term consequences.
Cost- And Time-Effective Strategies For Patients With Diarrhea
1. Consider minimizing testing in those with acute
gastroenteritis by obtaining an adequate history and
performing a sufficient physical examination.
Routine laboratory testing is unhelpful for most patients with
acute diarrheal illnesses. The white blood cell count is neither
sensitive nor specific for any particular illness characterized
by diarrhea. The white blood cell differential is often similarly
unhelpful. Hemoglobin and hematocrit levels may be useful
in those patients with blood loss, but otherwise are of limited
to no value. Electrolytes are rarely disordered significantly in
young patients with short periods of diarrhea. Renal function
tests are a poor screen for dehydration. Urine-specific gravity
may be somewhat more helpful, but easily observable clinical
features like skin perfusion, vital signs, urine output, and
thirst may be best of all.
Caveat: The WBC count can be helpful in identifying C.
difficile (which may require admission) or enteric fever. In
addition, eosinophilia may indicate alternative diagnoses.